One of the applications of microfluidic ejection structures is to jet a solution on to another device where a secondary function may be performed. A common secondary function is to vaporize a solution using a heater such that the contents of the solution can be vaporized so as to deliver the solution as a gaseous substance. Applications of such technology include, but are not limited to, metering and vaporizing device for electronic cigarettes, vapor therapy, gaseous pharmaceutical delivery, vapor phase reactions for micro-labs, and the like. In all of these applications, a microfluidic ejection head is used to eject fluid onto a heated surface for vaporization of the fluid into a discharge conduit. For some applications, the fluids to be ejected have relatively low vaporization temperatures and thus can evaporate over time through ejection nozzles in the ejection head. For other applications, contamination of the ejection head between uses may be a problem. In some applications, the fluids may leave a residue on the ejection head that will, over time, inhibit the proper ejection of fluid from the ejection head or that may plug the ejection nozzles. Maintaining such devices so that precise fluid ejection is obtained is a problem due to the small size of such devices. Conventional maintenance devices for microfluidic ejection heads require a relatively large area for cleaning the ejection heads.
Accordingly, what is needed is a maintenance apparatus that can be operated to clean the ejection head in order to maintain proper ejection of fluid.
In view of the foregoing, an embodiment of the disclosure provides a maintenance apparatus for a fluid ejection and vaporization device. The maintenance apparatus includes a movable wiper blade, the wiper blade being attached to an arm on one end of the arm, wherein a distal end of the arm is attached to an air operated mechanism for moving the arm and for causing a sweeping movement of the wiper blade over an ejection head in the fluid ejection and vaporization device.
In another embodiment there is provided a method for maintaining the cleanliness of an ejection head in a fluid ejection and vaporization device having a source of air flow through the fluid ejection and vaporization device. The method includes providing, within the fluid ejection and vaporization device, a movable wiper blade, the wiper blade being attached to an arm on one end of the arm, wherein a distal end of the arm is attached to an air operated mechanism for moving the arm and for causing a sweeping movement of the wiper blade over an ejection head in the fluid ejection and vaporization device. A flow of air is caused to flow through the fluid ejection and vaporization device in an amount sufficient to cause movement of the wiper blade in a sweeping motion from a first position to a second position across the ejection head.
In some embodiments, the air operated mechanism is biased by a biasing device in order to return the wiper blade to the first position from the second position when the flow of air ceases.
In other embodiments, the air operated mechanism is selected from an air bladder, a spring bellows, and an air operated flapper.
In one embodiment, the air operated mechanism is an air operated flapper having a spring for biasing the air flapper to the first position.
In some embodiments, air is caused to flow through the fluid ejection and vaporization device by inhaling vapors generated by the fluid ejection and vaporization device.
In other embodiments, the wiper blade is disposed between an ejection head and a vaporizing heater in the fluid ejection and vaporization device.
In another embodiment, the air operated mechanism is disposed on a mouthpiece side of the vaporizing heater between the vaporizing heater and mouthpiece of the fluid ejection and vaporization device.
In some embodiments, the fluid ejection and vaporization device is an electronic cigarette.